Originally Posted by
tdracer
<SNIP>
I'm not sure comparisons to BA38 are particularly apt - that was basically a normal touchdown that happened to occur short of the runway with the gear coming off because they sank in the mud - not the high G vertical hit that this appears to have been.
If we assume that a lightning strike did take out multiple electrical systems, this is really worrisome. As I posted earlier, lightning is designed for and the technologies involved are fairly mature. While it can do localized damage at the attach/detach points, it should never take down essential or critical electrical systems. Further, even with FBW and FADEC common place since the mid 1980s, I can't think of a single case where a lightning strike did take down such a system.
This could point to a build quality issue (lightning protection is highly dependent on the integrity of bonding and grounding - a single high resistance electrical connection (and we're talking mili-ohms here) can ruin a systems lightning protection. Maintaining those low resistance bonds on aging aircraft is a big concern - but the Superjet hasn't been around long enough for that to be a likely issue.
Or, it could point to a problem with the existing standards, in which thousands of in-service aircraft could be at risk.
The BA58 comparision was for fuel leakage from tanks when the UC is ripped off, that is similar to both this crash and the earlier SJ-100 heavy landing. Lightning protection is ever evolving and as said earlier new construction techniques like carbon composite are a challenge. Electronic devices (inside equipment) are also using smaller geometries and lower voltages potentially making them more vunerable. Even existing standards are subject to review and change. It used to be a 0.08" (2.0mm) aluminium alloy skin was acceptable for a integral tank wall without further analysis or protection, now you have to justify it.
These are my own opinions and may not reflect those of my employer).